For lathes



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Letters' Patent No. 83,774, 'dated November 3, 1868.

IMPROVE!) l.ADJUS'.IABL'Il-'i' GEARING FOR LATHE The Schedule referred to in these Letters Patent and making part of the same.

To all whomfit may concern;

Be it known that I, J ons Hunrnnnrs, of Chico-l pee, Hampden county, Commonwealth of Massachusetts, have invented a new and use-ful' Adjustable Gear for ScrewCutting Lathes; and I do hereby declare that the following is a full and clear description thereof, reference being had to the accompanying (huwin'gs, and to the letters of refe-rence marked thereon. l

In the drawings- Figure I is a side view of my device;

Figure II, a detailed view of a part of the same;

Figures III and Illare detail end and bot-toni views of part of the device; and' Figure V, a diagram of a part. This invention consistsof a new and simple device,

`by which the use of sepa-rate gear-wheels may be dispensed with in screw-cutting lathes. Itis well known that a great deal of trouble arises in a workshop from the mislaying and losing of the gear-wheels used for changing the inclination of the. screw-cutting devices in this kind of lathes; these wheels being made in sets of all sizes, and requiring to be numbered.`

This shaft A. 'has on one endn gear-wheel, B, which l engages with the gear running the traveller-screw C, and is pladiubeaiings underneath the belt-pulleyD. Parallel t6 the shait A, and about on the sanne hori zontal plane, is placed a shait,'E, which has a gear, F, on one en'd, engaging with other gear operated n'nne-` diately by the belt-pulley D, and on this shaft is a traveller, G, carrying gear-wheels H and I, meshing with eachother, the one, H, being turned by the shaft E,

by means of a key, a, and the gear I being shaiied in the traveller, which is free ,to turn on the shaft E, or .to slide upon it with the gear .H and I, the key a sliding in a groove, 1;, in the shaft, so that the shaft E, in revolving, operates thegearH and I without communicating any motion to the traveller G. On the underneath side of the traveller is a projection, K, which rests upon a rack, L, placed at an angle to the shafts A and E, and parallel to the 'line of decrease of the gear zz, as they are iixed upon the shaft A. There are as many projecting teeth to the rack L as there are gear x rv, and these come opposite each other, so that when the. Atraveller G rests upon a projecting tooth, c, as shown iu Fig.- IV, the gear I meshes with the gear X,Yopposite, so that when the traveller ismoved to any posit-ion upon the shaft E, that will bring it to rest upon a projecting tooth, c, of the rack, the machine is ready to cut the number of thread determined by the number of gear a: communicating motion from the shaft E to the one, A, and, consequently, the screw O, operating the traveller ofthe machine.

'In order to move the4 travellerlG, I use a lever, m, which is kept in position by means of a pin, u, put through it into holes in the side of the 4machine-bed.

Theseholes are numbered with the numbers ofthe gear which thc positions of the lever bring into play. Different armingen'icnts of this lever may be made without altering any principle involved.

An arrangement for bringing diferentfsized gear into connection between the pulley-gear and shaft E is shown in' Fig. II and Fig. I. This consists of a lever, OJzpivated upon the cent-re, correspondingto the centre of the shaft E, and having gear P and Q shafted upon it in such a manner that either may be brought between thegear on the shaft E and that on the belt-pulley. This lever is held in place by a pin, It, in either position.

n The spaces .between the gear :u x, on the shaft A, are necessary, in order to allow the gear-wheel I to free itself from the gear X in being moved, and to cuter the next mesh, and the notches between the projections on the rack also assist this operation, by

allowing the nave-ller, with the gear I, to fall back as it is moved.

Various unimportant changes may be made in this device, without altering the principle clearly shown. For insta-nce, the shaft A may be set at an inclination to the shaft E, and the gear used between them be bevelled to correspond with bevelled gear 'z 2:.

Eig` V shows a view -of the scale for indicating the place-to pin the lever m, inv order/fo set such gearin positionne will produce the desired number of thread.

.the 1nachiue,he only has to move the lever operating the traveller, and reiix it in the place indicated by the required number, and can double the number of gear used, in effect, by the use of the lever O, with its gear I and Q.

Now; having described my. invention,

What Iclam as new, and desire to secure by l. The combination ofthe shaitrA, having the gear :zr-:v arranged upon it, the shaft E, with traveller G, and the rack L, the parts being arranged and constructed substantially' in the manner shown and'for the purpose set forth.

2. In combination with the rest of my device, as herein sho'wn,the arrangement of the lever O, with gear I) and Q, substantially as here described, and for the purpose set forth.

3. In combination with the gear :t x and traveller G the dial-plate or index W, with the different sizes otl gear numbered upon it, substantially as herein described.

' JOHN HUMIHREYS.

Witnesses:

1t. l?. HYDE, E. 

